Apparatus for determining gauge of metal strip



Dec. 16, 1947. w CROTHERS r AL 2,432,727

APPARATUS FOR DETERMINING GAUGE or METAL STRIP Filed May 31, 1944 5Sheets-Sheet 2 1947- I R. w. CROTHERS ET AL 2.432.727

APPARATUS FOR DETERMINING GAUGE 0F METAL STRIP Filed llay 31, 1944 5Sheets-Sheet 4 INVENTORS ROBE/Pfl KCROTHERS ana'EDW/NE VoNA DA,

by: V Q g f e/rAf/wwey.

Patented Dec. 1 1941 APPARATUS FOR DETERMINING GAUGE OF METAL STRIPRobert W. Crothers, Pittsburgh, and Edwin E.

Vonada, McKecsport, Pa.

Application May 31, 1944, Serial No. 538,148

6 Claims. 1

In the production of metal strip, such as steel strip,'ior example, itis very desirable to know the average thickness or gauge of the stripafter it has been cold reduced, and prior to further processing.

In the past, prior to the present invention, average gauge could not bechecked while the strip was being rolled and coiled on a reel, averagegauge being checked by weight after the strips or sheets were sheared tosize. Such procedure required further processing after being coldreduced, this processing requiring about two weeks before the gauge ofthe sheets could be checked.

Therefore, it was possible for many coils of strip made during thesaidperiod of time to beofI- gauge, this oil-gauge being strip that does notmeet gauge tolerances specified bythe order.

Proposals have been made for determining instantaneous gauge whilerolling. However, all of such proposals are unsatisfactory andunreliable in performance. Thus, it is customary practice to attempt toshow instantaneous gauge a on a meter connected to a so-called flyingmicrometer which is an electric limit gauging device of a known type.Such device is intended to show instantaneous thickness of steel stripabout two inches from the edge as it is being coiled. However, heat inthe device and wave motion of the strip cause the meter to show offgaugeon the high side, which makes the operator think that the strip is beingrolled too thick. In order to correct this apparent off-gauge, theoperator adjusts the rolls tobring them closer together until the meterindicates the proper gauge, whereas, in reality. the strip is off-gaugeon the low side. Furthermore, the adjustment of the rolls isaccomplished by application of screw pressure on the ends of the rolls.Such pressure causes the rolls to bend very slightly, but measurably,resulting in a crown being rolled in the strip along the center portionsthereof.

An additional prior procedure constitutes actual measurement of theradial thickness of a certain number of wraps on the coil alter thematerial is rolled. This is a direct radial measurement between twomarkers placed in the coil after it is rolled. The mill operator placestwo markers between the wraps of the coil after it is formed on thereel. These markers project from the end of the coil and the distancebetween them is measured by hand after the coil is re- -moved from thecoiler mandrel.

The present invention provides an apparatus and mode of operation foraccurately determining the average gauge without delay and withoutrequiring preliminary preparation or special attention to obtain thedesired results. In accordance with the present invention, the gauge ofthe strip also may be determined in a portion of a coil and thenecessary adjustments made on the mill to change the gauge before therolling of the coil is completed. Generally speaking, the presentinvention provides apparatus for determining reliably the averagethickness, or gauge, of the strip as it is finished and coiled in coldreduction mills.

The apparatus of the present invention provides an accurate procedureand means of checking the average gauge of the strip as it is coiled atthe mill. The gauge is read directly from a prepared chart.

The apparatus of the present invention is based on the principle thatthe number of feet of strip which is required to make any particularnumber of wraps around a mandrel or part of a coil is a function or thegauge. This principle is used at two successive portions of the coil. Inoperation, the number of feet of strip is measured over a'. guide rollerwhile six hundred revolutions of the reel are counted. The number orfeet of strip is recorded on a first recorder for the first threehundred revolutions of the reel and on a second and similar recorder forthe second three hundred revolutions of the reel. The transfer from thefirst recorder to the second recorder is accomplished by two similarpreset counting devices. The number of feet required for the first threehundred wraps is subtracted from the lineal feet of strip in the secondthree hundred wraps. This diflerence multiplied by a factor, 0.00002122,which will be derived hereinafter, gives the actual average thickness ofthe strip.

The above referred to elements of the apparatus o! the present inventionwill be described in particularity hereinafter.

The invention will be understood more readily by reference to theaccompanying drawings, wherein:

Figure 1 is a diagrammatic plan view of the finishing end of a coldreduction strip mill with the apparatus of the present invention appliedthereto;

Figures 1A and 12B, taken together, constitute a. physical wiringdiagram of preset and recording counting mechanism employed in thepresent invention, the views showing the -mechanical construction ofthese mechanisms, as well as the electrical connections thereof;

Figure 2 is a fragmentary sectional elevation of a coiling end oi a coldreduction mill, taken on line II-II of Figure 1, looking in thedirection of the arrows;

Figure 3 is a fragmentary sectional elevation of the apparatus shown inFigure 1, the view being taken as looking along the line IIIIII ofFigure 1, in the direction of the arrows;

Figure 4 is a view similar to Figure 3 but looking at right angles toFigure 3;

Figure 5 is a fragmentary side elevation showing the mounting of atiming switch at the coiler;

Figure 6 is a schematic wiring diagram of the system;

Figure '7 is a graph of average gauge values plotted from data obtainedby operation of the present mechanism;

Figure 8 is a front view of a switch member on the coiler shown inFigure 5, the view being taken at right angles to Figure 5; and

Figure 9 is an enlarged view showing the ratchet 31 and associatedmechanism, it being understood that the same mechanism is used inconjunction with ratchet 24.

It will be understood that the strip is being rolled through acontinuous train of mills.

The foregoing statements will be amplified and explained hereinafter asthe description proceeds. It is realized that in the above, and in thefollowing description, customarily used reference characters have beensupplemented by designations or self-explanatory characters as adding toclarity of understanding in reading the wiring diagrams. It may be notedin this connection, that each particular unit employed in the system ofthe invention, is a known standard device, procurable on the openmarket.

The designations as employed in the wiring diagram of Figures 1A, 1B and6, are reproduced on the drawings under the legend Key of Figure 6, forclarity and are self-explanatory.

Reference again may be had to the details shown on the drawings, itbeing understood that the invention includes the interrelationship ofthe various units and the coordinated functions of operation resultingfrom such interrelationship, rather than, primarily, in the mechanicalconstructions of the units themselves.

The invention will be understood more readily from the accompanyingdrawings, wherein A represents the last stand of rolls in a coldreduction mill, the rolls of which are mounted in frame 3.. The strip,of which the gauge to be determined, is indicated at C, the strip, asfinished in the roll stand A being wound on coiler D, which is poweredby a motor E. The motor E drives the coiler D through suitable speedreducing mechanism F. A guide roll G for the strip is mounted betweenroll stand A and the coiler D.

It will be observed from Figure 3 that the guide roll G has mounted onits shaft. a pinion I00, which engagesa gear I02x mounted on a shaftI04. The shaft I04 is mounted in suitable hearings in bracket I05carried by frame member I08. Shaft I04 is shown as carrying a cam I,which is rotatable with the shaft, rotation of the cam I actuating thecontacts 2 of SW-I (Figure 3) to close and open these contactssuccessively, responsively to rotation of gear I02 and shaft I04, uideroller G being actuated by the strip passing thereover.

Switch SW2 is so connected to the reel to send an impulse to coils 22and 34 of the Preset counters for each revolution of the reel.

Switch SW-I is so connected and geared to the guide roll A to send animpulse to coils I8 4 or I9 of Recording foot counters RFCI or RFC-4 foreach five feet of strip travel.

Switch SW2 is mounted on the coiler D, it being actuated by a cam 3 onshaft H0 rotatably mounted on bearing II2, the shaft Il0 being connectedto a shaft II4 driven by shaft H6 of the coiler D. Cam 3 actuatescontacts 4 of SW--2 tomake and break these contacts.

The electrical connections through switches SWI and SW2 will be broughtout as the description proceeds. The construction is such that a speeddifferential exists between cams I and 3, and the contacts 2 and 4 areheld closed through 180 of the cam travel.

The ratchet devices which are included in the two revolution countersboth receive impulses continuously from the reel-operated switch duringthe first period of three hundred revolutions of the reel, and duringthis time the first foot counter receives impulses from the guide rollswitch. The ratchet device of the second revolution counter engages nocounting or other mechanism during this period, but the ratchet deviceof the first revolution counter is kept in engagement during this timewith a counting and screw feed device preset to open and close certaincontacts at the completion of three hundred revolutions. The switchingoperation thereby effected cuts off the impulses to the first revolutioncounter and puts the ratchet device of the second into engagement withits counting and screw feed device, and at the same time transfers theimpulses of the guide roll switch from the first foot counter to thesecond. After the second period of three hundred revolutions, the screwfeed device of the second revolution counter moves other contacts withthe effect of disengaging the counting and screw feeding device of thesecond revolution counter and disconnecting the second foot counter. Thetwo footage values can then be read off, from which the average gaugecan be calculated or determined by use of the chart of Figure 7. Each ofthe revolution counters incorporates a return sprin and stop inconnection with its counting and feed screw devices so that it returnsto its original preset condition as soon as it is disengaged from itsratchet device.

Reference now may be had to Figures 1A and 1B, with particular referenceto the mechanical features shown.

Preset counter No, 1 (PCI) includes a clutch member CL-I, actuated asfollows:

An electromagnetic coil 35 is mounted as shown on one arm II! of aclutch frame H8, energizing of coil 35 moving a pivoted sliding yoke I20against tension of spring I22 until the sliding yoke engages arm I I1about which the coil is wound. Coil 35 and arm III thereby constitute anelectromagnet of which the sliding yoke I20 is the armature, and arm IIIis the core. Yoke I20 has a bifurcated end I23 into which is received a.shaft I24, which is slidably mounted in suitable supports, not shown,and which carries a ratchet wheel 31 keyed thereon, and friction clutchdisc 36, so that when coil 35 is energized so as to pull over yoke I20,clutch disc 36 engages complementary disc 35a mounted on a shaft I26.Shaft I25 carries a pinion 38 which meshes with gear 33 on a stub shaftI28.

to be referred to hereinafter in greater I45 is provided for spectively,detail. A spring return shaft I28.

As is apparent, the purpose of spring I45 in the apparatus of thepresent invention is to return the nut 40 to its original or homeposition after trip 48 has contacted bar 41 and deenergized clutch CL-Iand coil AC-I. One end of this spring is securely fastened to shaft I28,while the other end is held stationary. This rotation of shaft I28 putsa tension in'the spring I45 which is released, after clutch plates 38and 380 are disengaged, by rotating shaft I28 in the opposite directionuntil nut 40 contacts stop gear 52 which is locked in position bypresetting dial I48. Gear 82 thus represents a. stop associated with thespring return.

Ratchet wheel 31 requires a reverse motion preventing means tocounteract the backlash tendency of spring I45 while the clutch-plates38 and 88a are engaged. This reverse motion preventing means consists ofa small dog 310 which is pin mounted at one end while the opposite endengages the ratchet teeth. Thus, when the wheel 31 moves forward, thedog merely slips from one notch to that following, but looks in placewhen wheel 31 tends to revolve in a reverse direction.

The above described movement of the yoke I20 to shift the shaftv I24 asdescribed above, brings ratchet wheel 31 into engagement with a bar I48,which bar is actually a part of arm 33 which constitutes an armature foran electromagnetic coil (AC-I), which is indicated at 34. Each time coil34 is energized, it brings pivoted arm 33 into engagement with it,thereby causing the bar I48 to transmit a. mechanical impulse to ratchet31 to advance gear 40 alon screw 4| towards contact bar 41, as will beapparent from the' drawings. When coil 34 is not energized, sprin I49holds the bar I48 out of engagement from the ratchet wheel 31.

In addition to its above described function, yoke I20 is an actuatingmember for a group of electrical contacts. The yoke I20 carries an armI50 extending horizontally from the yoke at right angles thereto. ArmI50 carries an L-shaped contact member I52 on its end, the member I52carryin a contact 43 adapted to engage a complementary contact 43 on anupturned end I54 of the contact frame member I30. Arm I50 also carriescontact member I58, which is mounted on arm I in any suitable manner,the contact member I58 carrying contacts 42' and 44 which are adapted toengage with contacts 42 and 44 on contact member I30.

. The mechanical elements on No. 2 Preset counter (PC-4), are similar,in general, in construction and operation, to the foregoing features ofNo. 1 Preset counter. Reference, however, may be made to the illustratedconstruction, which likewise embraces an electromagnetic clutch CL2.This clutch includes coil 23, which is mounted as shown, on an arm I58of a clutch frame I80, an energizing of the coil 23 moving a yoke barI82 against tension of spring I84, which 'spring normally holds yoke barI82 out of engagement with arm I58, the electromagnetic clutch beingactuated by coil 23 and yoke bar I82 as the movable armature contacttherefor.

The-yoke bar I82 has a bifurcated end I88 which fits over clutch shaftI88, which is slidably mounted in suitable supports, not shown, andwhich carries a ratchet wheel 24 keyed thereon, together with a frictionclutch disc 28a, so that when coil 28 is energized to pullover yoke bar6 I 82, clutch disc 25a engages its complementary disc '25 mounted on ashaft I10. This shaft I10 carries a pinion 28 which meshes with a gear21 on a shaft I12.

This gear 21 meshes with a nut 28 mounted on a fixed screw 29 until trip48 on the nut comes into contact with a bar 49,-this latter being oneside of a contact frame I14. This frame I14 has an upstanding contactlug I18 thereon on which is mounted contactl 30, which contact isadapted to engage complementary contact 30a on arm I18. This arm I18 ismounted on a bar I80, this latter bar being mounted in turn on yoke barI82.

Yoke bar I has its free end off-set into an L-shaped contactmember I82,this member I82 carrying a. contact element 3| adapted to engage acomplementary contactelement 3| a on arm I84 of frame I14.

A spring I88 is provided to return the nut 28 to its original positionafter trip 48 has contacted bar 49 and deenergized clutch CL--2 and coilAC--2. One end of the spring is securely fastened to shaft I12, whilethe other end is held stationary. Rotation of shaft I12 puts tension onthe spring I 88 which is released after clutch disks 25 and 25a aredisengaged, by rotating shaft I12 in the opposite direction until nut 28contacts stop gear 53 which is locked in position by presetting dialI88. Gear 53 thus represents a stop associated with the spring return.Ratchet wheel 24 requires a reverse motion preventing means tocounteract the backlash tendency of spring I88 while clutch plates 25and 25a are engaged. This reverse motion preventing means consists of asmall dog 24a which is pin mounted at one end while the opposite endengages the ratchet teeth.

Thus when the wheel '24 moves forward the dog merely slips from onenotch to that following, but locks in place when wheel 24 tends torevolve in a reverse direction.

Energizing coil 23 moves yoke bar I80 towards the right, as viewed inFigure 1A, thereby engaging clutch discs 25, 25a, this movement beingdirected against tension of the spring I64. Also, as

viewed in Figure 1A, this movement will close cclintacts 30 and 30a andopen contacts 3| and 3 a. I

A pinion 53 on screw 29 meshes with an elongated gear 5i which moves apointer 32 overthe counting range dial I88, the gear 5| being movedforward responsively to engagement of the ratchet wheel 24 with arm I90of movable contact ele-v ment 2| each time coil 22 is energized. Theenergizing of the coil 22 thereby causes the arm I 90 to transmit amechanical impulse to the ratchet wheel 24, each impulse causing thegear 28 to move along fixed screw 29 with respect to contact arm 49.

Reference now may be had to Figure 1B for the mechanical construction ofthe control relays and the recording foot counters.

No. 1 Control relay (CR,I) includes a coil I2 Fixed 1 contact arm I98has contact element I0 thereon, contact element I0 being adapted toengage thecomplementary contact element I0a, which is carried on amovable contact arm I I, which, in turnf wound on a bracket I92 of astand I94.

is controlled by tension of a spring I98.

No. 2 Control relay (ca-2) includes a coil 9' wound on a bracket 200 ofa stand 202. "mica contact, arm 204 of the stand carries three contactelements i, 8 and 1, adapted to engage complementary contact elements5a, 8a and 1a on movablecontact arm 8, which is controlled by a springThe Recording foot counters (RPC -i and RFC-4) are ratchet type,advancing a dial one figure for each impulse. n Recording root counterRFC-4, a coil i2 is mounted on arm 252 as shown. When the coil i2 isenergized, it draws arm am against the tension of spring 2, this actionengaging pawl arm 214 into a notch oi ratchet wheel i2 mounted on ashaft 2", which carries dial I4.

The Recording foot counter No, 2 is constructed similarly. Coil i9 ismounted on arm 2", so that when energized, arm 2" is moved againsttension of the spring 220 into engagement with the arm 2l6. Thismovement engages pawl arm 222 into a notch or ratchet wheel [5, which ismounted on a shaft 224, thereby moving dial l6 one notch.

The electrical system and sequence of operations may now be referred to,reference being had to the wiring diagrams, Figures 6 and 1A and 1B.

The device is set into operation when a push button PB is held closed bythe operator, and cams I and 2 on the switches SW-l and SW-2 are in suchposition that the contacts 2 and 4 are closed. This is accomplishedinstantly because a speed differential exists between cams i and 2, andthe contacts 2 and 4 are held closed through 130 of cam travel.

Switches SWi and SW--2 are driven mechanically. When push button PB isclosed and held in until the cams on SW-i and SW--2 are both in positionto hold their respective switches closed, current flows from lineconductor L-l through conductor 2l8, contact 4 of switch SW-2, conductor220, push button PB, conductor 222', relay coil i2 of control relay CRI,conductor 224, coritact 2 on SW|, through conductor 226 toline conductorL--2. This energizes the coil l2 of control relay CR-l, which closesnormally open contacts I0, Inn on the control relay CRI.

When contacts 12, lfla on CR| close, relay coil 9 of control relay, CR2is energized, through a circuit consisting of the line conductor L-l,conductor 240, contact ID of CRl, conductors 242 and 244, relay coil 9of control relay CR2, conductor 246 and back to line L-2.

Energizing of coil 9 of CR2 closes a self-holding circuit which consistsof conductor 242, which connects line conductor Li to contacts in and 6on control relay CR-2, thence through conductor 250, thence throughcontacts 2ia, 2| on the clutch (CL-4) of No. 2 Preset counter (PC-2),thence through conductor 252 which taps into conductor 244. Thisself-holding circuit holds the entire system in operation throughout itsentire cycle.

Furthermore, energizing coil 9 of control relay CR--2, completes animpulse circuit to the preset counter coil 22 of Preset counter No. 2(PC-2). This impulse circuit starts from conductor 220, throughconductor 228, through conductor 224 to normally open contacts a, and 5,now closed responsively to energizing coil 9, of control relay CR-2,through conductor 236 to coil 22, that is, coil AC2, both designationsbeing used in order to conform to Figure 1A, of Preset counter No. 2,and thence through conductor 228 to line conductor L-2.

The energizing of the coil 9 also results in closing of contacts 1, 1aon Control relay No. 2. This closing of contacts I, la energizes coil 35of'clutch CL-i of Preset counter No. 1, through conductor 254 tocontacts 1, 1a of Control relay No. 2 to conductor 256 to coil '35 ofclutch CLI of Preset counter No. 1, to conductor 252 to 8 power lineL-2. This energizes coil 25 of clutch CL-l.

when clutch coil 25 is ene l the follflwlnl actions take place:

Contacts 44 and 44 on clutch CLI or Preset counter No. 1 close, andpermit impulses to enersize coil 24 of Preset counter No. 1, through acircuit which comprises conductor 224, conductors 222 and 2254, throughclosed contacts 44' and 44 of clutch CL-i, through conductor 222 to coil24 ct Preset counter No. 1, th n through 0011- ductor 222 to conductorline L-2.

Closing of clutch CL-l also completes a circuit through now closedcontacts 42', 42 to coil i2 oi'Recording foot counter RFC-l, the circuitbeing from the line conductor L--i through conductor 256 to contacts 42,42 on clutch CL-i, thence through conductor 255 to coil ll of RFC- I,through conductor 212 to conductor 224 to contacts 2 or switch SW-l,thence through conductor 226 to power line conductor L-2, Energizingcoil 12 through impulses from the switch 'SW-i actuates the countermechanism of Recording foot counter RFC-l.

At the end of the preset counting setting of clutch CL-I, contacts 42and 42' of the clutch close, energizing coil 22 of clutch CL--2 ofPreset counter No. 2. This causes the counting mechanism of Presetcounter No. 2 to start functioning. Coil 22 is energized from the powerline conductor L-l through conductor 250, thence through contact 42 ofPreset counter No. 1, through conductor 262, thence through coil 22 ofPreset counter No. 2, thence through conductor 264 to power lineconductor L-2.

At the end of the predetermined setting on Preset counter No. 1,contacts 44, 44' or this Preset counter open, thereby breaking theimpulse circuit to coil 24 of Preset counter No. 1. Opening of contacts44, 44 opens contacts 42, 42' of clutch CL-i of Preset counter 1,breaking the impulse circuit of coil ll of Recording foot counter 1,thus stopping the count for this part of the cycle.

Normally closed contacts 42, 42' of clutch CL- I, open when coil 26 isenergized, then close at the end of the preset counting cycle,energizing coil 22 oi clutch CL--2 of Preset counter No. 2, which startsthe counting actuation oi Preset counter No. 2.

As soon as coil 22 is energized, contacts 22, 22a of clutch CL-2 close,allowing impulses from switch SW-i to energize coil is of RFC No. 2through a circuit from power line L- -l through conductor 265 tocontacts 26a and 20 of Preset counter No. 2 through conductor 212.through coil i2 01 Recording foot counter No. 2, through conductor 214to conductor 224 to contacts 2 of switch SW-I. through conductor 226 toline conduct-or L-2.

Counter RFC-2 continues to pick up the impulses until the predeterminedcount of Preset counter No. 2 is reached, when contacts 2| and 2m onPreset counter No. 2 open, thereby deenergizing coil 2 of Control relayCHI-2.

With the push button PB and contacts 2 and 4 in the closed positions,coil 12 of Control relay CR-l is energized, causing armature ii tooperate, closing contacts ll, Ila.

With contacts II and Ilia closed, coil 2 on Control relay CR-2 isenergized, closing contacts 5 and 5a, 5 and 6a, and I and 1a oi! Controlrelay CR-2. Contacts 6 and 5a being closed, coil 2 on Control relayCR--2 is held in through contacts 2|, 2hr on clutch CL2 oi Presetcounter No. 2, which contacts remain closed at all times until opened atthe end of the operation to reset the mechanism. Contacts 1 and la areheld closed by coil 9 on Control relay Cit-2, and thus energizing coil35 on clutch CL-l of Preset counter No. 1. Contacts and 5a held closedby coil 3 on Control relay CR-2, and send impulses from switch SW-2 tocoil 22 of Preset counter No. 2. 4

Coil 35 of Preset counter N0. 1 is held closed by contacts I and 1a onControl relay CR-2, thereby closing contacts 44 and 44' of clutch CL--iof Preset counter No. 1. Contacts 42 and 42' on clutch CL-l of Presetcounter No; 1, also being held closed, send impulses to energize coil I8on Recording foot counter RFC-4, through contacts 2 on switch SW-i eachtime contacts 2 close. This coil i3 operates ratchet i3, advancing diall4 one step or number ahead'with each impulse received.

Each instant the contacts 2 on switch SW| close, coil 34 on Presetcounter No. 1 and coil 22 on Preset counter No. 2 will move ratchetwheels 24 and 31 one notch ahead.

As has been indicated previously, coil 35 on clutch CL-i is energizedthrough contacts I and la, when clutch members 36 will beclosed,connecting the ratchet 31 to gear train 33, 33, which gear train drivesthe nut 40 on fixed screw 4! until thetrip point 43 comes into contactwith bar 41. At this point, contacts 42, 42' and 44, 44 open andcontacts 43, 43' close.

This action stops Preset counter No. 1 from operating. It also stopsRecording foot counter RFC-4 from operatin and energizes coil 23 onPreset counter No. 2, closing clutch members 25,

,25a, thereby connecting gear train 26, 21, 23 to ratchet 34 on Presetcounter No. 2.

Coil 23 of clutch CL-2 of Preset counter No. 2 closes contacts 33, 33a,contacts 3|, 3ia remaining closed. Cell 22 of the Preset counter No. 2,still receiving impulses from contacts 4 on switch SW--2, causes theratchet to advance the gear train 23, 21, 23 which drives gear 28 along9, fixed screw 23 until trip point 43 comes into contact with bar 49,thereby opening contacts 33, 30a and 3!, Ma. This stops coil 13 onRecording foot counter RFC-2 from receiving impulses from contacts 2 onswitch SWI f and opening of contacts 3| and 3 la deenergizes coil 3 ofControl relay CR-2. The mechanism thus is reset for the next operation.

When clutches 25 and 33 are opened, gears 28 and 43 automatically returnto their original or "home position, which is determined by the dis- Itracted from the number of feet on RFC-2, and this answer multiplied bya constant K obtained from the equation derived and described asfollows:

From the equation: Area of the ring between two circles of radius R1 andB: one of which encloses the other equals Pi(R2-'R1'), the followingequation can be set tance the gears 52 and 33 have been moved along thestationary screws 23 and 4| by the arrows 32 and 45 that are connectedto gears II and 33, respectively. Arrows 32 and 43 have been calibratedso the number on the race thereof will be the required number ofimpulses to move gears 23 and 40 to the trip position.

Preset counters No. 1 and No. 2 are so set on dials 32 and 43 to require300 impulses in 0011 22 or 34 to trip arm 41 and 43. 7

Therefore dial l4 on RFC--1 will record the number oi lineal feet orstrip traveling over guide roll A while Preset counter No. 1 ismeasuring 300 impulses. When Preset counter No. 1 transfers to Presetcounter No. 2, then RFC-4 receives impulses to record the number oflineal feet passing over guide roller A. While Preset counter No. 2 ismeasuring 300'impulses. At the end of this 300 count, the number or feeton RFC-4 is subtimes mandrel It can be assumed that A1=Gauge (G) timesthe feet (S1) between R and R1; and

A2=Gauge (G) times the feet (S2) between R1 and R2.

Substituting in (3), we have SiG=21rRG Rev1+1r(G Revi) in sq. ft.

or, solving for R (5) 21! Rev Substituting (5) in (4) I A Rev +G Rev infeet Substituting for A: and clearing:

(21' Rev,)

expressed in sq. it.

Also, the following equation can be set up: Substituting for A: andclearing:

expressed in sq. ft.

G=12 a- S1) This last is the general equation:

Using the general equation and substituting the preset countersettings, 1. e. Rev: equals 300 and Rev: equals 300, we have G equals(182-8001))002122 11 any desired preset counter setting. or the generalequation can be used for any set up as long as the respectiverevolutions and feet are measured simultaneously in each area.

We claim:

1. Apparatus for enabling determination of average thickness of metallicstrip passing to a reel from a roll stand while the strip is moving andbeing continuously coiled on the reel, which comprises in combination,counting means for counting revolutions of the reel, instrumentalitiesfor measuring lineal feet of strip passing to the reel during thecounting of the revolutions, electrical connections for the saidrevolution counting means and lineal feet measuring in:- strumentalitiesfor producing simultaneous operation thereof, and controlinstrumentalities therefor for initiating starting thereof and forstopping the revolution counting means and the lineal feet measuringinstrumentalities after the counting of a predetermined number ofrevolutions of the reel.

2. Apparatus for enabling determination of average thickness of metallicstrip passing to a reel from a roll stand while the strip iscontinuously moving and being continuously coiled on the reel, whichapparatus comprises, in combination, first and second preset countinginstrumentalities for counting revolutions of the reel, first and secondrecording foot counters for measuring lineal feet of strip during apredetermined number of revolutions of the reel, instrumentalities forswitching the counting and measuring from the first preset counter andfirst recording foot counter responsively to the first preset countercompleting the counting of the said predetermined number of revolutionsof the reel, and means for stopping operation of the second presetcounter and second recording foot counter responsively to completion ofcounting of the predetermined number of revolutions of the reel by thesecond preset counter.

3. Apparatus for enabling determination 'of average thickness ofmetallic strip passing to a reel from a roll stand while the strip iscontinuously moving and being continuously coiled on the reel, whichapparatus comprises, in combination, first and second preset countinginstrumentalities for counting revolutions of the reel, first and secondrecording foot counters for measuring lineal feet of strip during apredetermined number of revolutions of the reel, control switchinstrumentalities for controlling operation of the first and secondpreset counting instrumentalities and first and-second recording footcounters, a

. l2 cording foot counter to the second preset countinginstrumentalities and second recording loot counter responsively tocompletion of coimting of a predetermined number of revolutions of thereel, while the reel continues to revolve, and means on the controlswitches for stopping actuation of the said second preset countinginstrumentalities and second recording foot counter responsively tocompletion of counting of a second predetermined number of revolutionsof the reel.

4. Apparatus for enabling determination of average thickness of strippassing to a reel while the strip is moving and being continuouslycoiled on the reel, which comprises in combination, counting means forcounting revolutions of the reel, instrumentalities for measuring thelength of strip passing to the reel during the counting of therevolutions, means for producing simultaneous operation of the saidrevolution counting means and length measuring instrumentalities, andcontrol instrumentalities therefor for initiating starting thereof andfor stopping the revolution counting means and the length measuringinstrumentalities after the counting of a predetermined number ofrevolutions o! the reel.

5. Apparatus for enabling determination of average thickness of strippassing to a reel while the strip is moving and being continuouslycoiled on the reel, which comprises in combination, counting means forcounting revolutions of the reel, instrumentalities for measuring thelength of strip passing to the reel during the counting of therevolutions, means for producing simultaneous operation of the saidrevolution counting means and length measuring instrumentalities. andcontrol instrumentalities for simultaneously stopping the revolutioncounting means and the length measuring instrumentalities after thecounting of a predetermined number of revolutions of the reel.

6. Apparatus for enabling determination 0! average thickness of strippassing to a reel while the strip is continuously moving and beingcontinuously coiled on the reel, which apparatus comprises, incombination, first and second preset counting instrumentalities forcounting revolutions of the reel, first and second instrumentalities formeasuring the length of strip during a predetermined number ofrevolutions of the reel, instrumentalities for switching the countingand measuring from the first preset counter and first length measuringinstrumentality when the first preset counter completes the counting ofthe. said predetermined number of revolutions of the reel, and means forstopping operation of the second preset counter and second lengthmeasuring instrumentality when the second preset counter completes thecounting of the predetermined number of revolutions of the reel.

ROBERT W. CROTHERS. EDWIN E, VONADA.

